The spur of the moment theft of a trailer by an occasional malevolent or impecunious miscreant has long since been supplanted by the organized theft of mainly the most desirable trailers, by determined if not professional thieves. Thus, over the past decade or more, a plethora of locking devices have been offered to owners of trailers, to discourage, if not prevent the stealing of trailers by trailer thieves.
Locking devices fall into two main categories which may be described as follows:
A. Those devices in which it is immediately evident how the locking function is accomplished, and the degree of effort that will likely be required to defeat the locking mechanism without rendering the hitch unserviceable.
B. Those devices in which the general means of locking the hitch is not readily evident. It is difficult to discover how the locking means operates, and therefore, how to defeat it.
In devices falling in category A the thief can estimate the time, the tools and the type of skillful effort which will be required to defeat the locking mechanism, and then more or less predictably assess the risk of executing his task. An obviously abundantly fortified hitch will pose so evidently formidable a challenge that it will generally invite no more than fleeting interest on the part of the thief. In category B, the thief must take the time to make a relatively close examination of unpredictable duration just to analyze how the mechanism works, correctly conclude how it does, and then formulate a plan to defeat it. A successful locking device in either category forces the thief to turn his attention to a hitch which appears to be unprotected by a locking device.
When under the foregoing circumstances, the thief seeks an apparently unprotected trailer hitch, and encounters a trailer hitch which utilizes the instant invention, he is surprised to find it is locked. His initial scrutiny reveals there is no visible locking means, adding to his surprise. Finally, when an even further scrutiny reveals that the locking means is effectively concealed; that, access to what appears to be the locking member cannot be gained with conventional tools; and, that the end of the locking member, which end is only visible by looking upwards from an essentially supine position on the ground below the hitch, requires a special key means, his surprise gives way to a realization that his attention will be more profitably transferred to a less arcane challenge.
The locking means of this invention comprises a locking-ball in which is concealed a threaded bolt, so as to give the impression that the hitch is unprotected. It neither advertises that it is highly secure, nor that it is locked at all, yet upon close examination reveals a locked mechanism with no visible locking means, and no visible modification of either the hitch, or what appears to be a conventional ball. Even after a thief acquaints himself with the device, the obvious difficulty of successfully defeating it within a reasonable period of time without damaging the hitch, inspires in a prospective thief a reluctance to risk an attempt to defeat the device. This device clearly does not belong in category A, and is more likely to be classified in category B.
Some prior art devices lock the trailer hitch to the conventional ball carried by the tow vehicle. Such devices protect the trailer from being disconnected from the tow vehicle when both are parked, and left unattended. These devices generally also protect the trailer when it is disconnected, this protection being typically provided by inserting a spare ball as a plug in the spherical socket of the hitch. The hitch is closed with a lever, hand-wheel or other cam-actuating means, and then the closed hitch is locked with the locking device. Some typical such devices are disclosed in U.S. Pat. Nos. 3,391,555; 3,514,980 and 3,820,823 inter alia.
Other prior art devices are specifically designed to protect a trailer which has been disconnected from its tow vehicle. Typical of such devices are plugs, or devices which effectively bar access of a ball into the socket of the trailer hitch. Such devices are those disclosed in U.S. Pat. Nos. 3,226,133; 3,526,110; 3,810,664; and 3,977,210 inter alia. Though this invention can be used in the former category, that is to lock the trailer hitch to the ball, while the hitch and ball couple the tow-vehicle and trailer, it is more specifically directed to locking the trailer hitch after the tow vehicle is uncoupled.
It should be borne in mind that the thief for whom this invention is conceived, can steal a trailer, no matter how carefully it is secured, if the thief is given more than sixty seconds of reasonably assured quiet and inattention. Under such a circumstance, even a hasp (saddle member) of the locking device of U.S. Pat. No. 3,391,555 presents no serious obstacle to a chisel or cutting torch. Exposed parts and locks, as recognized in U.S. Pat. No. 3,526,110 are vulnerable to a force sufficient to deflect or break them, yet insufficient to damage the trailer hitch so that it can still be used to tow the trailer away. Even a heavy padlock used in the device of U.S. Pat. No. 3,237,969 is easily cut with a portable torch, or is susceptible to being defeated by acid poured into the lock. Alternatively, the lock is frozen by a cryogen until the hasp is brittle, and then the hasp is fractured. These nowstandard tampering techniques are favored because they are quiet and quick, and do not require carrying a miniature oxy-acetylene or similar torch, or other specialized tools, the possession of which may be a little difficult to explain to law enforcement authorities.
As has been stated, and as will be readily recognized, a proficient thief, given enough time, can mount a determined assault on any locked trailer hitch and successfully force it to yield its prize. A trailer hitch deemed sufficiently secure, would be one which dissuades such an assault in the first place. The only theft-proof trailer hitch is the unassaulted hitch. If the hitch does not always succeed in dissuading an assault, it should be eminently evident that a successful assault will necessitate more time than a thief might reasonably plan to allot, and, that the assault will necessarily attract more attention than the thief is willing to tolerate. Finally, it should be soon apparent to the thief that even a successful high-risk assault on the trailer hitch additionally presents so great a risk that the hitch will probably be damaged so as to be unusable, that, on balance, he is dissuaded from making the assault.
As self-evident as the foregoing observations may appear, it is apparent that they are not always used as the principal guiding tenets in the design of most prior art locking devices for trailer hitches or trailer couplings. A padlock clearly does not afford more than a modicum of invulnerability, and the challenge it presents can generally be gauged by a casual visual assessment. Plugs present a greater challenge because it is not immediately apparent that they conceal a locking device, as for example the plug of U.S. Pat. No. 3,810,664, but such a plug is relatively expensive to manufacture and requires specialized tooling to do so. The simple fact is that in their enthusiasm to provide diverse locking means for trailer hitches, those skilled in the art have overlooked some concepts of locking a hitch, one of which concepts, adequately embodied in suitable structure, provides a locking device which is as effective as it is simple in operation, and inexpensive to manufacture. This invention provides a locking means based on the simple concept that a hardened steel bolt concealed within a ball, is a highly effective deterrent for a trailer thief.